You can keep records of which card is linked to which account to make it easier. I send myself an email.

I have done this a few times and in my experience your purchase can be anything, including gift cards! Most Best Buys have variable load Visa Gift Cards of up to $200 that have a surcharge of $6. You can also buy Amazon gift cards with no surcharge.

For every $250 you spend at Best Buy you will also get a $5 gift card if you are a Best Buy Reward Zone member, which is free to join. The $5 gift certificates can be used to buy Amazon gift cards.